#include <stdio.h>   /* vsprintf */
#include <stdarg.h>  /* ANSI C header file */
#include <syslog.h>  /* for syslog() */
#include <stdlib.h>  /* exit */
#include <errno.h>   /* errno */
#include <string.h>  /* strlen */
#include "error.h"

#define MAXLINE 4096 /* max text line length */

int daemon_proc;     /* set nonzero by daemon_init() */

static void err_doit (int, int, const char *, va_list);
/*
 * Nonfatal error related to system call
 * Print message and return
 */
void err_ret (const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    err_doit(1, LOG_INFO, fmt, ap);
    va_end(ap);

    return;
}

/*
 * Fatal error related to system call
 * Print message and terminate
 */
void err_sys (const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    err_doit(1, LOG_ERR, fmt, ap);
    va_end(ap);
    exit(1);
}

/*
 * Fatal error related to system call
 * Print message, dump core, and terminate
 */
void err_dump (const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    err_doit(1, LOG_ERR, fmt, ap);
    va_end(ap);
    abort();    /* dump core and terminate */
    exit(1);    /* shouldn't get here */
}

/*
 * Nonfatal error unrelated to system call
 * Print message and return
 */
void err_msg (const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    err_doit(0, LOG_INFO, fmt, ap);
    va_end(ap);

    return;
}

/*
 * Fatal error unrelated to system call
 * Print message and terminate
 */
void err_quit (const char *fmt, ...)
{
    va_list ap;

    va_start(ap, fmt);
    err_doit(0, LOG_ERR, fmt, ap);
    va_end(ap);
    exit(1);
}

/*
 * Print message and return to caller
 * Caller specifies "errnoflag" and "level"
 */
static void err_doit (int errnoflag, int level, const char *fmt, va_list ap)
{
    int     errno_save, n;
    char    buf[MAXLINE + 1];

    errno_save = errno; /* value caller might want printed */
#ifdef HAVE_VSNPRINTF
    vsnprintf(buf, MAXLINE, fmt, ap);   /* safe */
#else
    vsprintf(buf, fmt, ap); /* not safe */
#endif
    n = strlen(buf);
    if (errnoflag) {
        snprintf(buf + n, MAXLINE - n, ": %s", strerror(errno_save));
    }
    strcat(buf, "\n");

    if (daemon_proc) {
        syslog(level, buf);
    } else {
        fflush(stdout); /* in case stdout and stderr are the same */
        fputs(buf, stderr);
        fflush(stderr);
    }
    return;
}
